||It has been suggested that this article be merged with Spermatogenesis. (Discuss) Proposed since January 2012.|
Spermatocytogenesis is the male form of gametocytogenesis and involves stem cells dividing to replace themselves and to produce a population of cells destined to become mature sperm.
Three functionally separate spermatogonial cell types are recognised on the basis of the appearance of the nuclei: type A dark spermatogonia (Ad), type A pale spermatogonia (Ap), and type B spermatogonia (B).
Type Ad spermatogonia ("dark")
The population of spermatogonia is maintained by type Ad spermatogonia. These cells do not directly participate in producing sperm and simply ensure a supply of stem cells to participate in spermatogenesis is maintained.
This type divides to produce one type Ad spermatogonia that can carry on spermatogenesis and one type Ap spermatogonia that can be further differentiated.
Type Ap spermatogonia ("pale")
Type Ap spermatogonia repeatedly divide mitotically to produce identical cell clones linked by cytoplasmic bridges.
The connections between cells allow development to be synchronised. When repeated division ceases, the cells differentiate into type B spermatagonia. This stage is referred to as the spermatogonial phase.
Type B spermatogonia
Type B spermatogonia undergo mitosis to produce diploid intermediate cells called primary spermatocytes.
- CLERMONT, Yves (March 1966). "Renewal of spermatogonia in man". American Journal of Anatomy 118 (2): 509–524. doi:10.1002/aja.1001180211.